Originally Posted by
Bush65
Illustration of type RLD governor as fitted to the A series injection pump used on Isuzu 4BD1 and 4BD1-T.
Black smoke is a result of fuel that has not been burnt completely - often because there was not enough air (could be other reasons such as poor fuel atomisation).
The air may be restricted somewhere in the intake/filtration system.
Turbocharges are great for diesel engines, which like high air/fuel ratios - low air/fuel (rich) results in black smoke and higher exhaust gas temperature.
The maximum fuel adjustment on the governor is easy to adjust for more fuel when a turbo is fitted. This is usually required to get more boost pressure (unless the turbo fitted is on the small side).
Several threads in this forum go into more detail on fitting a turbo. From memory the most recent was started by Isuzurover a few months ago.